fix.OptionMapFlatMap.scala Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of scalafix-rules_2.12 Show documentation

scalafix rules

The newest version!

package fix

import scala.meta.Case
import scala.meta.Pat
import scala.meta.Term
import scala.meta.XtensionCollectionLikeUI
import scala.meta.inputs.Position
import scalafix.Patch
import scalafix.lint.Diagnostic
import scalafix.lint.LintSeverity
import scalafix.v1.SyntacticDocument
import scalafix.v1.SyntacticRule
import scalafix.v1.XtensionSeqPatch

class OptionMapFlatMap extends SyntacticRule("OptionMapFlatMap") {
  private object CaseSome {
    def unapply(c: Case): Boolean = PartialFunction.cond(c) {
      case Case(
            Pat.Extract.Initial(Term.Name("Some"), Pat.Var(Term.Name(a1)) :: Nil),
            None,
            _
          ) =>
        true
    }
  }

  private object NoneToNone {
    def unapply(c: Case): Boolean = PartialFunction.cond(c) {
      case Case(
            Term.Name("None") | Pat.Wildcard(),
            None,
            Term.Name("None")
          ) =>
        true
    }
  }

  override def fix(implicit doc: SyntacticDocument): Patch = {
    doc.tree.collect {
      case t @ Term.Match.After_4_4_5(_, CaseSome() :: NoneToNone() :: Nil, _) =>
        Patch.lint(OptionMapFlatMapWarn(t.pos))
      case t @ Term.Match.After_4_4_5(_, NoneToNone() :: CaseSome() :: Nil, _) =>
        Patch.lint(OptionMapFlatMapWarn(t.pos))
      case t @ Term.PartialFunction(CaseSome() :: NoneToNone() :: Nil) =>
        Patch.lint(OptionMapFlatMapWarn(t.pos))
      case t @ Term.PartialFunction(NoneToNone() :: CaseSome() :: Nil) =>
        Patch.lint(OptionMapFlatMapWarn(t.pos))
    }.asPatch
  }
}

case class OptionMapFlatMapWarn(override val position: Position) extends Diagnostic {
  override def message = "maybe you can use Option#map or flatMap"
  override def severity: LintSeverity = LintSeverity.Warning
}